Toddler Suddenly Waking up at Night

Children are not supposed to take Melatonin !! Why would you let your child cry ? Would you like it if you were left alone crying and no one gave a damn ? Why is it that parents justify letting their infant/child cry just because ? It's pathetic. A child is crying because they are in distress and want soothing and nurturing - not your turned back and neglect. You don't have to understand all of this, just be there to soothe your child. Your child will be old before you know it, and there will be no more sleepless nights - just an empty house - and you will miss those days. Parents need to realize that part of being a parent with an infant/child are sleepless nights, everyone experiences it.
Does your child have a regular night time routine ? Kids need routine in their lives - bath, storytime, maybe sing some songs, prayer, etc. Nightly. Your child also needs to know that you will be there when he/she needs you. So what is the harm staying with your child comforting him ? Your child needs to build trust, and this is a way to bond with them. Like I said, these years go by so quickly, and you will regret your behavior if you do the idiotic thing of ignoring your childs' cries, fears, etc.
One thing that will calm your child (and is a SAFE thing for children) is called moon drops. You can find them at your local health store or online cheaper (even amazon has them). They are a little soft vanilla lozenge that tastes great, and will let your child sleep through the night. They are also great for adults and for long overseas flights. They are non addicting, homeopathic and amazing.
Your child could be distressed for many things, things you and I may not see. My children have the ability to see 'the other side' and have told me of some of the scary things that I do not see, but have actually caught on my camera at various times. You cannot deny what you cannot see - just as many who believe in God don't see him, but believe in Him - its called Faith. Have faith in your child that what they are saying is true and do not ever tell them 'oh that's not so, or I don't believe that' It very well could be true....
Sorry to go so personal on this but felt I needed to let you know some things that many do not ever consider.....read some of the articles below, this may not apply to your child (but it explains a lot about my own).....

http://www.amazon.com/Historical-Remedies-Homeopathic-The...

http://www.childrenlights.com/Articles/the_children.htm

http://www.experiencefestival.com/wp/article/crystal-chil...

My 2.5 year old is doing the stay with me part when putting him down. He would come up with any excuse to try to keep us in there. Cover me - you are covered. What do you need? - ummmmmm (looking around his room for something, anything. I'm not sure what it is, but we did have to do the cry it out. We tried only responding if he called out our names, but wasn't whining/screaming, but that became every 2 minutes. We tried only going in when he was really worked up and telling him to calm down. All this did was make it worse. We just went cold turkey. If he is crying (really crying, not the fake whiny/cry), we go in. Sometimes he has bumped his head, etc. Otherwise, once the door is shut, it is shut. It hasn't stopped it, but it has helped.

We had a week or two of the nighttime wake ups. I think that you may be too active with him at night. Go in, ask what is wrong, give him a hug, rub his back, and tell him that you need him to sleep. Have him repeat what you need him to do, then leave. You may have crying for a little bit. My son actually once told my husband to go put on a shirt, so my husband said ok, and my son fell back asleep. Other times he wanted to get up and play. We got the My Tot Clock so that we could tell him that it was still blue, and what does blue mean? - sleep.

You will get through this, just find what works for all of you, and hopefully you will be getting some sleep soon.

It sounds like it's just a few minutes so that's probably easier on you all than having him cry.

Does he have or need a nightlight? How about changing his sheets and having him help so he knows they're together just right?

Also, with the holidays, his schedule is probably a bit different. As hard as it is, keep his life normal like it is the rest of the year. Also, we've had some pretty intense weather lately. Any chance that's waking him? It woke my family last night.

Has anything recently changed at your house? He could be having nightmares. He might not remember the dreams but they wake him. If you put him to sleep on his right side he is less likely to have nightmares. Most of us turn over when we wake up and that erases the dream therefore he cannot remember it only that he is disturbed and upset.
Does he have a nightlight?
Sometimes when my children were upset I would fix a bed for that child on the floor in our bedroom. That seemed to do the trick.
One of my daughters would tell me her whole day from the last thing that happened to the first. I listened to her nightly until she was almost twelve years old. This eased her mind and she seldom took a problem from one day into the next.

My 2.5 year old is doing the same thing! He wants his blankets fixed, water, song etc. We were just discussing this last night (at 3 am) and I think we're going to go the cold turkey route. The only problem with this is his sister in the next room and waking her up. Hopefully it will go quickly and we will have some peaceful holidays!
Good luck & I'll let you know what happens with us,
S.

A couple of things to consider: teething and growth spurt. It is temporary, you will get a full nights sleep again :)